It doesn't really find A1, but once you found it yourself it tells you if
it's lowercase or not. Close enough ?
=EXACT(A1,LOWER(A1))
=EXACT("@#$%&*! details!",LOWER("@#$%&*! details!"))
The string doesn't consist exclusively of lower case characters. If the OP means
cells that contain only lower case text if they contain any text, with all
nontext characters ignored, then EXACT(x,LOWER(x)) works. Otherwise, see below.
If you mean all characters in the cell must be lower case letters, then try
something like this. Define the following two names.
Seq referring to =ROW(INDIRECT("1:1024"))
LowerAlpha referring to ="abcdefghijklmnopqrstuvwxyz"
Then use formulas like
=ISNUMBER(SUMPRODUCT(FIND(MID(A1,Seq,1),LowerAlpha)))
To find the first cell in A1:A100 containing only lower case letters, try the
array formula
=MATCH(TRUE,MMULT(--ISNUMBER(FIND(MID(A1:A100,TRANSPOSE(Seq),1),LowerAlpha)),
Seq^0)=COUNT(Seq),0)